Overview
Kaposi sarcoma grows from the cells lining blood and lymph vessels. Lesions may stay on the skin or affect the mouth, gut, lungs, or lymph nodes.
In people with HIV, starting or improving HIV treatment often makes it shrink. Other treatments include local therapy, radiation, and chemotherapy.
Symptoms
Common signs:
- Purple, red, or brown flat patches or bumps on the skin
- Patches inside the mouth
Less common
- Swelling of the legs
- Cough or shortness of breath (lungs)
- Belly pain or bleeding (gut)
Look up a symptom: Dark spots or patches on the skin · Mouth sore, or white or red patch, that won't heal · Red spot, bump, or patch on the skin · Swollen ankles, feet, or both legs
When to get medical care
Causes
Changes in a cell's genes that make it grow out of control. Most happen by chance; some are linked to the risk factors below or to inherited genes.
Does it spread or run in families?
- Cancer isn't contagious. You can't catch it from someone.
Who is more likely to get it
- HIV
- Organ transplant drugs
- Older men of Mediterranean, Eastern European Jewish, or African descent
Diagnosis
Tests look for the cause. Many people checked for these symptoms turn out not to have cancer.
Questions you may be asked
- When symptoms started and whether they're getting worse
- Family history of cancer
- Past illnesses, treatments, and exposures
The exam
A physical exam, focused on where the symptoms are.
Tests
Tests, if needed:
- Skin biopsy:
- HIV test:
- Endoscopy or chest CT: If organs might be involved.
Treatment
Treatment depends on the type, stage, and your overall health. A cancer care team makes a plan with you.
Self-care
- Write down symptoms and when they started
- Bring someone with you to appointments
- Ask for copies of test results
- Ask about clinical trials: they can offer new treatments
- Quit smoking: it helps at every stage
HIV treatment, local treatments, radiation, or chemotherapy.
Prevention
To lower risk or find it early:
- HIV testing and treatment
- PrEP to prevent HIV
Which doctor treats this
- Start with your primary care provider (family doctor or internist).
- They may send you to an oncologist (cancer doctor), often working with surgeons and radiation doctors.
Living with it
- Keep a simple notebook of symptoms, medicines, and questions for visits.
- Ask for a survivorship care plan when treatment ends.
- Gentle activity, like walking, can ease tiredness.
- A cancer diagnosis can affect mood. Tell the care team if you or your family feel down or anxious.
Support groups and helplines
- American Cancer Society: Help 24/7 at 1-800-227-2345, rides to treatment, and support programs.
- National Cancer Institute: Cancer Information Service: Free answers from cancer information specialists: 1-800-422-6237.
Back to school, work, or sports
- Many people keep working during or after treatment.
- Ask about changes that help, like flexible hours. Workers may be covered by the ADA.
Pregnancy and breastfeeding
- If you're pregnant or planning to be, tell your cancer team. Some treatments can harm a baby.
- Ask about saving eggs or sperm before treatment if you may want children later.
For caregivers
- Go to visits when you can and take notes.
- Keep a list of medicines, allergies, and doctors in one place.
- Learn the warning signs that need fast care, like fever during treatment.
- Take breaks and ask for help. Caregivers need care too.
Outlook
Outlook depends on the type and stage. Cancers found early are usually easier to treat, and treatments keep improving.
Support is available: ask about social workers, nutrition help, and support groups.
Getting ready for your visit
Bring a list of symptoms and medicines.
What to bring
- A list of medicines and supplements
- Notes on when symptoms started
- Past test results and scans
Questions to ask
- Does it involve any organs?
- Will my HIV treatment help shrink it?
- What stage is it, and what are the treatment options?
- Are there clinical trials for me?
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Sources
Last updated 2026-11-13.